Coupling

ABSTRACT

The invention relates to a rotationally symmetrical coupling comprising an annular hub made of a rigid material, which is surrounded by an outer ring made of a rubber-elastic material. The coupling also comprises an outer contouring, which is located on the outer diameter and which is provided for positively transmitting torques, whereby the outer ring is reinforced by an embedded, annular, rigid solid body. The aim of the invention is to achieve a quieter operation of a coupling of the aforementioned type and to better protect this coupling from becoming damaged. To these ends, the invention provides that the rubber-elastic material is silicone and that the annular, rigid solid body, on the outside, has a shape, which is similar to that of the outer contouring of the outer ring and which maintains, over the circumference, a nearly constant distance from the outer contouring of the outer ring. The rigid solid body is preferably comprised of a curved, metallic strip material having a constant thickness.

CROSS REFERENCE TO RELATED APPLICATIONS

Applicants claim priority under 35 U.S.C. §119 of German Application No.200 18 823.2 filed Nov. 3, 2000. Applicants also claim priority under 35U.S.C. §365 of PCT/EP01/12738 filed Nov. 2, 2001. The internationalapplication under PCT article 21(2) was not published in English.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a rotationally symmetrical coupling comprisingan annular hub that is made of a substantially rigid material andsurrounded by an outer ring made of a rubber-elastic material, as wellas an outer contouring that is located on the outer diameter and isprovided for positively transmitting torques, whereby a substantiallyring-shaped, rigid solid body is embedded in the rubber-elastic materialof the outer ring near the outer contouring. Said solid body has anouter contouring as well, whereby individual shaped elements of theouter contouring of the ring-shaped, rigid solid body protrude radiallyfrom the inside outwards into individual shaped elements of the outercontouring.

2. The Prior Art

In connection with a coupling of the type specified above that is knownin the prior art, the embedded solid body consists of a rigid metallicring, to which a radial protrusion is welded as well to each site wherethe outer ring made of rubber-elastic material has a radial protrusion.In that connection, the layer of rubber-elastic material covering themetallic ring is very thin in each of the areas of the protrusions andin each center between two projections, but otherwise very thick. Theconsequence thereof is that the elastic properties at each of the pointsalong the circumference of the outer ring where the load in introducedare very uneven, which may lead to a rough operation of the coupling andto damage of the outer contouring. Such damage is particularly criticalif such damage leads to any direct contact between the embedded solidbody and machine elements located downstream, or to contact withaggressive media.

SUMMARY OF THE INVENTION

Therefore, an object of the invention is to further develop the couplingof the type specified above in that it will run operate in a quietermanner and be protected against damage in a superior way.

For achieving this object, provision is made according to the inventionbased on a coupling of the type specified above that the material withthe elasticity of rubber is silicone, and that the outwardly pointingshape of the ring-shaped, rigid solid body is similar to the outercontouring of the outer ring and has a nearly constant distance from theouter contouring of the outer ring over the circumference. In this way,the elastic properties of the coupling in each of the sites where theload is introduced are always identical, and it is ensured that no localload concentrations will occur in the silicone material. The probabilityof notches developing in the elastic outer ring is reduced by usingsilicone material. Furthermore, the ring-shaped, rigid solid body iscompletely covered outwards by the chemically highly resistant siliconelayer.

According to a particularly preferred embodiment of the invention,provision is made that the ring-shaped, rigid solid body consists ofcurved metallic strip material having a constant thickness. Such anembodiment of the ring-shaped solid body is particularly favorable interms of costs. Furthermore, the required rigidity of the reinforcingsolid body can be determined in a particularly simple manner by thethickness of the strip material used. For example, the rigid,ring-shaped solid body can be dimensioned taking into account compatiblerigidity jumps.

Furthermore, provision is made that the ring-shaped, rigid solid body ismade of aluminum or an aluminum alloy. Aluminum strip material can beprocessed in a particularly simple manner to the rigid ring employedaccording to the invention; it has a low specific weight and it isbonding with the adjacent silicone material in an excellent way.

Finally, provision is made that the rigid solid body is completelysurrounded by a layer of silicone material. A particularly good supportof the solid body is ensured by completely embedding the rigid solidbody in aluminum. In addition, the rigid solid body is well-protectedall around against any access of aggressive media.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is explained in the following in greater detail with thehelp of a special exemplified embodiment and by reference to variousdrawings. The following is shown in the drawings:

FIG. 1 is a side view of a coupling as defined by the invention.

FIG. 2 is a section through a coupling as defined by the inventionaccording to section C-D in FIG. 1.

FIG. 3 is a section through a coupling as defined by the inventionaccording to section A-B shown in FIG. 1.

FIG. 4 shows a ring-shaped, rigid solid body as defined by theinvention; and

FIG. 5 is a section through the rigid solid body as defined by theinvention in FIG. 4 according to section E-F shown in FIG. 4.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 shows a coupling 1 as defined by the invention that is comprisedof a metallic hub 2 and an elastic outer ring 3 made of silicone, whichadjoins said hub radially on the outside. On its outside diameter 4, theouter ring 3 has an outer contouring 5, via which it is transmitting thetorque introduced via the hub 2 to machine elements located downstream.

For supporting the individual shaped elements 6 of the outer contouring5 of the outer ring 3, a ring-shaped, rigid solid body 7 made ofaluminum strip having a uniform thickness is embedded in the siliconematerial of the outer ring 3. Like the outer ring 3, the ring-shaped,rigid solid body 7 is provided with an outer contouring 7 a formed fromsemicircular shaped elements 7 b or molded cavities 8. The ring-shaped,rigid solid body 7 is completely surrounded by the silicone material, sothat radially outwards, a uniformly thick layer 9 of silicone materialis obtained around the ring-shaped, rigid solid body 7.

The introduction of force from the shaft not shown into the hub 2 takesplace via the axial bores 10. Centering bores ensure a defined positionof the coupling 1 in relation to the shaft not shown. The markings 12and 13 are provided on the hub 2 and the outer ring 3, respectively, Anyperipheral offset of the markings 12 and 13 indicates a plasticdeformation of the outer ring 3.

In accordance with the specific load of the outer ring 3, whichdecreases as the radius increases, the cross section 14 of the outerring 3 is tapering as the diameter increases. For receiving thering-shaped, rigid solid body 7, the cross section 14 is widening againin such a manner that the ring-shaped, rigid solid body 7 is completelysurrounded by the silicone material of the outer ring.

1. A rotationally symmetrical coupling (1) comprising an annular hub (2)made of a substantially rigid material and surrounded by an outer ring(3) made of a rubber-elastic material, as well as an outer contouring(5) located on the outside diameter (4) for positively transmittingtorques, whereby in the outer ring (3) adjacent to its outer contouring(5), a substantially ring-shaped, rigid solid body (7) is embedded inthe rubber-elastic material of the outer ring (3), the latter having anouter contouring (7 a) as well; and whereby individual, shaped elements(7 b) of the outer contouring (7 a) of the ring-shaped, rigid solid bodyradially project into individual, shaped elements (6) of the outercontouring (5) of the outer ring (3) from the inside outwards, whereinthe rubber-elastic material is silicone, and that the outer contouring(7 a) of the ring-shaved, rigid solid body (7) forms a parallel contourto the outer contouring (5) of the outer ring (3) running in a constantdistance from the outer ring (3) over the circumference.
 2. The couplingaccording to claim 1, wherein the ring-shaped, rigid solid body (7)consists of curved, metallic strip material having a constant thickness.3. The coupling according to claim 1, wherein the ring-shaped, rigidsolid body (7) consists of aluminum or an aluminum alloy.
 4. Thecoupling according to claim 1, wherein the ring-shaped, rigid solid body(7) is completely surrounded by a layer of silicone material.